The shuttle effect of lithium polysulfides(LiPSs)and uncontrollable lithium dendrite growth seriously hinder the practical application of lithium-sulfur(Li-S)batteries.To simultaneously address such issues,monodispers...The shuttle effect of lithium polysulfides(LiPSs)and uncontrollable lithium dendrite growth seriously hinder the practical application of lithium-sulfur(Li-S)batteries.To simultaneously address such issues,monodispersed Nb N quantum dots anchored on nitrogen-doped hollow carbon nanorods(NbN@NHCR)are elaborately developed as efficient Li PSs immobilizer and Li stabilizer for high-performance Li-S full batteries.Density functional theory(DFT)calculations and experimental characterizations demonstrate that the sulfiphilic and lithiophilic NbN@NHCR hybrid can not only efficiently immobilize the soluble Li PSs and facilitate diffusion-conversion kinetics for alleviating the shuttling effect,but also homogenize the distribution of Li+ions and regulate uniform Li deposition for suppressing Li-dendrite growth.As a result,the assembled Li-S full batteries(NbN@NHCR-S||Nb N@NHCR-Li)deliver excellent long-term cycling stability with a low decay rate of 0.031%per cycle over 1000 cycles at high rate of 2 C.Even at a high S loading of 5.8 mg cm^(-2)and a low electrolyte/sulfur ratio of 5.2μL mg^(-1),a large areal capacity of 6.2 mA h cm^(-2)can be achieved in Li-S pouch cell at 0.1 C.This study provides a new perspective via designing a dual-functional sulfiphilic and lithiophilic hybrid to address serious issues of the shuttle effect of S cathode and dendrite growth of Li anode.展开更多
Development of cost-effective,efficient,and durable electrocatalysts for oxygen evolution reaction(OER)with fast kinetic reaction is highly significant,considering the elevated thermodynamic energy barrier involved in...Development of cost-effective,efficient,and durable electrocatalysts for oxygen evolution reaction(OER)with fast kinetic reaction is highly significant,considering the elevated thermodynamic energy barrier involved in water electrolysis.To overcome such challenges,an innovative vapor phased iron-doping strategy is employed on carbon nanotubes(CNT)-interlinked metalorganic framework(MOF)nanosheets(Ni-MOF@CNT)to obtain mixed metal oxide and metal heteronanoparticles superficially implanted partially(semi)-decomposed MOF nanosheets(Ni-M@C-400).These semi-MOF nanosheets attain the structural privileges related to MOF-nanostructure,mixed metal nanoparticles synergism,interconnected-CNT assisted high conductivity,and mechanical strength.As a result,Ni-M@C-400 exhibits exceptional OER activity with overpotential as low as 229 mV to reach the benchmark current density of 10 mA/cm^(2)(η10)and exhibits greatly reduced thermodynamic barrier(Tafel slopes of 40.51 mV/dec)along with significant durability for~60 h.More importantly,this sublimated iron-doped semi-MOF(Ni-M@C-400)displays significantly better OER performance over the corresponding annealed bimetallic MOF(NiFe-M@C-400:270 mV atη10).Moreover,the successful incorporation of vapor phased iron into variety of MOFs(Cr,Mn,Co,Ni,and Cu)approved its uniqueness and the universality.This work provides an innovative vapor phased heteroatom-doping strategy to develop costeffective and efficient electrocatalysts for water electrolysis.展开更多
Designing and fabricating the bifunctional electrocatalysts for the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)has long posed an uphill and pressing task for the interconversion of electricity and...Designing and fabricating the bifunctional electrocatalysts for the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)has long posed an uphill and pressing task for the interconversion of electricity and chemicals.Baring this in mind,herein,we propose a novel hierarchical nanoarchitecture of N-doped carbon nanotubes capped with carbon layer armored CoFe alloy(CoFe@NC-NT),which is facilely fabricated by spray drying and subsequent annealing process.As a bifunctional electrocatalyst,the well-designed CoFe@NC-NT shows a remarkably low overpotential of 257 mV and a half-wave potential of 0.74 V to obtain 10 mA·cm^(-2)in OER and ORR,respectively.Meanwhile,it is also characterized by exceptional operating stability to meet practical application for Zn-air batteries.The high catalytic activity of CoFe@NC-NT is attributed to the tight contact between the highly conductive nanotubes and metal alloy nanoparticles.And the qualified stability is ascribed to the coating effect of carbon layer shell to alloy core.Given the unique structural evolution with enhanced oxygen-involved reaction activity,we believe that this work can provide an appealing innovative approach towards the directed self-assembly of functional nanostructures to realize satisfying overall performance.展开更多
基金supported by the open research fund of Songshan Lake Materials Laboratory (2022SLABFN26)the National Natural Science Foundation of China (21773024)+1 种基金the Sichuan Science and Technology program (2020YJ0324,2020YJ0262)the Reformation and Development Funds for Local Region Universities from China Government in 2020 (ZCKJ 2020-11)。
文摘The shuttle effect of lithium polysulfides(LiPSs)and uncontrollable lithium dendrite growth seriously hinder the practical application of lithium-sulfur(Li-S)batteries.To simultaneously address such issues,monodispersed Nb N quantum dots anchored on nitrogen-doped hollow carbon nanorods(NbN@NHCR)are elaborately developed as efficient Li PSs immobilizer and Li stabilizer for high-performance Li-S full batteries.Density functional theory(DFT)calculations and experimental characterizations demonstrate that the sulfiphilic and lithiophilic NbN@NHCR hybrid can not only efficiently immobilize the soluble Li PSs and facilitate diffusion-conversion kinetics for alleviating the shuttling effect,but also homogenize the distribution of Li+ions and regulate uniform Li deposition for suppressing Li-dendrite growth.As a result,the assembled Li-S full batteries(NbN@NHCR-S||Nb N@NHCR-Li)deliver excellent long-term cycling stability with a low decay rate of 0.031%per cycle over 1000 cycles at high rate of 2 C.Even at a high S loading of 5.8 mg cm^(-2)and a low electrolyte/sulfur ratio of 5.2μL mg^(-1),a large areal capacity of 6.2 mA h cm^(-2)can be achieved in Li-S pouch cell at 0.1 C.This study provides a new perspective via designing a dual-functional sulfiphilic and lithiophilic hybrid to address serious issues of the shuttle effect of S cathode and dendrite growth of Li anode.
基金supported by the National Natural Science Foundation of China(Nos.21773024 and 52072310)Sichuan Science and Technology Program(No.20YYJC3786)+1 种基金China Postdoctoral Science Foundation(No.2019M663469)the Reformation and Development Funds for Local Region Universities from China Government in 2020(No.ZCKJ 2020-11).
文摘Development of cost-effective,efficient,and durable electrocatalysts for oxygen evolution reaction(OER)with fast kinetic reaction is highly significant,considering the elevated thermodynamic energy barrier involved in water electrolysis.To overcome such challenges,an innovative vapor phased iron-doping strategy is employed on carbon nanotubes(CNT)-interlinked metalorganic framework(MOF)nanosheets(Ni-MOF@CNT)to obtain mixed metal oxide and metal heteronanoparticles superficially implanted partially(semi)-decomposed MOF nanosheets(Ni-M@C-400).These semi-MOF nanosheets attain the structural privileges related to MOF-nanostructure,mixed metal nanoparticles synergism,interconnected-CNT assisted high conductivity,and mechanical strength.As a result,Ni-M@C-400 exhibits exceptional OER activity with overpotential as low as 229 mV to reach the benchmark current density of 10 mA/cm^(2)(η10)and exhibits greatly reduced thermodynamic barrier(Tafel slopes of 40.51 mV/dec)along with significant durability for~60 h.More importantly,this sublimated iron-doped semi-MOF(Ni-M@C-400)displays significantly better OER performance over the corresponding annealed bimetallic MOF(NiFe-M@C-400:270 mV atη10).Moreover,the successful incorporation of vapor phased iron into variety of MOFs(Cr,Mn,Co,Ni,and Cu)approved its uniqueness and the universality.This work provides an innovative vapor phased heteroatom-doping strategy to develop costeffective and efficient electrocatalysts for water electrolysis.
基金This research was supported by the National Natural Science Foundation of China(No.21773024)Sichuan Science and Technology program(Nos.2020YJ0324 and 2020YJ0262)+1 种基金Reformation and Development Funds for Local Region Universities from China Government in 2020(No.ZCKJ 2020-11)China Postdoctoral Science Foundation(No.2019M653376).
文摘Designing and fabricating the bifunctional electrocatalysts for the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)has long posed an uphill and pressing task for the interconversion of electricity and chemicals.Baring this in mind,herein,we propose a novel hierarchical nanoarchitecture of N-doped carbon nanotubes capped with carbon layer armored CoFe alloy(CoFe@NC-NT),which is facilely fabricated by spray drying and subsequent annealing process.As a bifunctional electrocatalyst,the well-designed CoFe@NC-NT shows a remarkably low overpotential of 257 mV and a half-wave potential of 0.74 V to obtain 10 mA·cm^(-2)in OER and ORR,respectively.Meanwhile,it is also characterized by exceptional operating stability to meet practical application for Zn-air batteries.The high catalytic activity of CoFe@NC-NT is attributed to the tight contact between the highly conductive nanotubes and metal alloy nanoparticles.And the qualified stability is ascribed to the coating effect of carbon layer shell to alloy core.Given the unique structural evolution with enhanced oxygen-involved reaction activity,we believe that this work can provide an appealing innovative approach towards the directed self-assembly of functional nanostructures to realize satisfying overall performance.
